Bathyarca philippiana ( Nyst, 1848 )

Negri, Mauro Pietro & Corselli, Cesare, 2016, Bathyal Mollusca from the cold-water coral biotope of Santa Maria di Leuca (Apulian margin, southern Italy), Zootaxa 4186 (1), pp. 1-97 : 23

Bathyarca philippiana ( Nyst, 1848)

Fig. 4 d–f

Arca obliqua Philippi, 1844 (p. 43, pl. 15, fig. 2) = invalid taxon.

Arca philippiana Nyst, 1848 (p. 54).

Bathyarca (Bathyarca) philippiana ( Nyst), 1848 — Caprotti 1968 (p. 93, pl. 1, figs. 5–7).

Bathyarca philippiana ( Nyst, 1848) — Nordsieck 1969 (p. 22, pl. 3, fig. 10.44); Cossignani et al. 1992 (fig. 265); Poppe & Goto 1993 (p. 44, pl. 3, fig. 4); Salas 1996 (p. 46); Giribet & Peñas 1997 (fig. 95); Giannuzzi-Savelli et al. 2001 (p. 80, fig. 104); Repetto et al. 2005 (p. 287, mid right fig.); Beck et al. 2006 (p. 95, bottom fig); De Frias Martins et al. 2009 (p. 67, figs. 301–302); Oliver et al. 2016 (online resource).

Bathyarca philippiana (Nyst) — Di Geronimo & Panetta 1973 (p. 97, pl. 3, fig. 1); Di Geronimo 1979[a] (p. 136, pl. 6, fig. 4).

? Bathyarca philippiana ( Nyst, 1848) —Mastrototaro et al. 2010 (fig. 5 g).

Diagnostic characters. Trigonal-ovate, markedly inequilateral, maximum shell growth posteroventrally; median radial depression from the beaks to the ventral margin; ventral margin with a shallow sinuation, more evident in juveniles; low commarginal cordlets crossed by numerous radial riblets; small, spatulate spines at the intersections, more raised on the posterior part. Prodissoconch: shell type ST-2D; length about 180 µm; roundish D-shaped outline; convex profile; P-1 surface smooth; P-2 reduced to metamorphic lip; transition to the nepioconch well marked, somewhat step-like.

Remarks. Bathyarca grenophia (Risso, 1826) is currently synonymized with the present taxon (CLEMAM 2016; WoRMS 2016); the specific name grenophia was rejected by ICZN Opinion 1887 (1998).

Occurrence. Box-corer samples BC04 (6 specimens), BC05 (12), BC11 (1), BC66 (18), BC67 (18), BC68 (1), BC70 (3), BC71 (7), BC72 (29); cores BC04 (5), BC05 (8), BC21 (16), BC51 (18), BC67 (7), BC72 (22). Maximum length: 6 mm.

Distribution and habitat. Bathyarca philippiana is distributed on both sides of the Atlantic (from the Gulf of Mexico to the Azores) and in the Mediterranean, also reaching the Levantine basin; it lives attached by byssus to stones, gravel and coral debris, from shelf edge to bathyal depths ( Poppe & Goto 1993; Pons-Moyà & Pons 1999; Galil 2004; Oliver et al. 2016). It was regarded as a preferential/accompanying element in CB (deep-sea white corals) biocoenosis (Di Geronimo 1979[a]; Di Geronimo & Bellagamba 1985). In the Santa Maria di Leuca CWC biotope, it was found on dead colonies of Madrepora oculata and hard substrates (Mastrototaro et al. 2010), being abundant in coral rubble, and common in solitary coral thanatofacies (Rosso et al. 2010).

Fossil record. Pliocene and Pleistocene of Italy ( Caprotti 1968; Di Geronimo 1979[a]; Di Geronimo & Bellagamba 1985).

Figures

FIGURE 4. a – c: Bathyarca pectunculoides (Scacchi, 1835); RV (a, b) and LV (c), sample BC 72, scale bars: 1 mm (a – b), 0.1 mm (c, prodissoconch); d – f: Bathyarca philippiana (Nyst, 1848); LV, sample BC 04, scale bars: 2 mm (d – e), 0.1 mm (f, prodissoconch); g – i: Dacrydium hyalinum (Monterosato, 1875); LV, sample BC 72, scale bars: 1 mm (g – h), 0.1 mm (i, prodissoconch); j – m: Pseudamussium peslutrae? (Linnaeus, 1771); LV, sample BC 67, scale bars: 2 mm (j – k), 0.1 mm (l, prodissoconch), 0.05 mm (m, P – 1 detail); n – q: Karnekampia sulcata (Müller, 1776); RV (o – q) and LV (n), sample BC 72, scale bars: 5 mm (n – p), 0.1 mm (q, prodissoconch).